Method and apparatus for controlling interrupts in a virtual machine system

[54] METHOD AND APPARATUS FOR CONTROLLING INTERRUPTS IN A VIRTUAL MACHINE SYSTEM

[75] Inventors: Toshio Hirosawa, Machida; Jun'ichi Kurihara, Hachioji; Shigemi Okumura, Kiyose, all of Japan

[73] Assignee: Hitachi, Ltd., Tokyo, Japan

[21] Appl. No.: 837,345

[22] Filed: Mar. 7,1986

[30] Foreign Application Priority Data

Mar. 11, 1985 [JP] Japan 60-46676

[51] Int. a* G06F 12/08; G06F 13/00

[52] U.S. CL 364/200

[58] Field of Search 364/200 MS File

[56] References Cited

U.S. PATENT DOCUMENTS

4,253,145 2/1981 Goldberg 364/200

4,400,769 8/1983 Kaneda et al 364/200

4,456,954 6/1984 Bullions, III et al 364/200

4,459,661 7/1984 Kaneda et al 364/200

4,564,903 1/1986 Guyette et al 364/200

Primary Examiner—Gareth D. Shaw

Assistant Examiner—Adolfo Ruiz

Attorney, Agent, or Firm—Antonelli, Terry & Wands

[57] ABSTRACT

At an occurrence of an interrupt, each entry of the vector table of the vitrual machine monitor to be referenced by the hardware of the bare machine is loaded with an address of an interrupt processing program of the running virtual machine for an interrupt number associated with the entry. When the interrupt is allowed to be directly processed by the virtual machine, the virtual machine monitor is not activated, that is, the interrupt processing program of the vitual machine can immediately execute the necessary processing, which eliminates the overhead associated with the intervention of the virtual machine monitor. Moreover, the content of the system stack pointer is set to point to the stack of the running virtual machine. Consequently, the content of the registers to be saved for an interrupt processing are directly stored in the stack of the running virtual machine, and therefore the overhead caused because the stack of the virtual machine monitor is used is removed.

6 Claims, 7 Drawing Sheets